金属有机框架类新型铁肥的研制

Developing new type of metal-organic framework iron fertilizer

为探索和评估Fe-MOF材料应用于铁肥的潜力,应用铁离子在温和的水热条件下合成铁基MOF(Fe-MOF)类新型铁肥,采用粉末X射线衍射(PXRD)、中红外光谱(FTIR-ATR)、X射线光电子能谱(XPS)以及扫描电子显微镜(SEM)等技术手段表征Fe-MOF的元素组成和结构特征,利用静水溶出和土壤培养试验探究其养分释放行为。结果显示,Fe-MOF由铁、氮、磷、碳、氧以及氢元素组成,其中铁的负载量达19.7%,三价铁和二价铁的物质的量比为1︰1,氮和磷的负载量分别为5.1%和14.7%;Fe-MOF在水溶液中84 d铁的累积释放率为4.7%,相应的在土壤中铁的累积释放率达到58.7%,呈现出优异的缓控释特征。研究表明,以环境友好型材料为底物,通过简便绿色的水热合成工艺,实现了微量元素(铁)和大量元素(氮、磷)的协同配伍和定向组装,为新型铁肥的研发提供了新途径。

Metal-organic framework(MOF)material is a class of ecologically and environmentally friendly and functional cluster compound,which can be pre-designed topologically to achieve targeted loading and complexation of specific nutrients at the molecular level.In this article,the iron ions were used to synthesize a new Fe based MOF(Fe-MOF)fertilizer under mild hydrothermal conditions to study and evaluate the potential of Fe-MOF materials for application in iron fertilizers.The elemental composition and structural features of Fe-MOF were characterized using techniques including powder X-ray diffraction(PXRD),mid infrared spectroscopy(FTIR ATR),X-ray photoelectron spectroscopy(XPS),and scanning electron microscopy(SEM).The behaviors of releasing nutrient were investigated by using hydrostatic dissolution and soil incubation experiments.The results showed that Fe-MOF was composed of iron,nitrogen,phosphorus,carbon,oxygen,and hydrogen elements,with a loading capacity of 19.7%for iron,a ratio of 1∶1 for trivalent and divalent iron,and a loading capacity of 5.1%and 14.7%for nitrogen and phosphorus,respectively.The cumulative release rate of iron in aqueous solution for 84 days was 4.7%,while the cumulative release rate in soil reached 58.7%,showing the characteristic of excellent slow and controlled release.It is indicated that the synergistic compatibility and directional assembly of trace elements(iron)and macro elements(nitrogen,phosphorus)have been achieved by using environmentally friendly materials as substrates and a simple and green process of hydrothermal synthesis.It will provide a feasible pathway for designing a new type of iron fertilizers.